There are two distinct regions of the Pacific ocean that we look at to investigate trends. The Nino 3 and Nino 3.4 are sections of the ocean along the equator that are monitored for changes in temperature. The threshold for El Niño in this area is +0.8 degrees, with current temperatures in Nino 3 being +0.7, but this is only one area to look at as temperature at depth is also important.

Figure 4. Sea surface temperature anomaly from March 30, 2017.

Measurements of ocean temperature is not only taken at the surface, but in most cases right down to the sea floor. This provides the opportunity to track the movement of ocean temperatures through the profile of the ocean.

Figure 3 demonstrates the change in ocean temperature at depth over a four-month period (December 2016 to March 2017).

As you can see the cooler (blue) water on the right side of the graph (representing ocean of the west coast of South America) gradually decreased in size over time. While warm water on the left side of the graph (representing ocean off Northern Australia) has increased and begun to displace the cool water and move east towards South America.

Figure 4. Pacific Ocean anomaly from December 2016 to March 2017.

For this movement of warm water to turn into an El Niño like pattern the trade winds would need to reverse and head in an east-west direction.

The following video demonstrates how the movement of cool and warm waters occurs showing the formation and reduction in the 2015 El Niño.

The Fast Break newsletter is produced by Agriculture Victoria and highlights what a set of models are indicating for the coming season. While models are currently sitting in the predictability barrier that occurs early in the year, there is some indication that the season may be dry and warm.

Through the Rural Industries and Research Development Corporation (RIRDC) funded ‘Improved use of seasonal forecasting to increase farmer profitability’ project, BCG is funded to facilitate a seasonal climate community of practice and extend learnings. The ‘community’ includes scientists, extension specialists, advisors and farmers from different agricultural sectors aiming to improve access to, and understanding of, forecasting information. For a farmer, this will lead to better application of the forecasting information and improved decision-making at the seasonal scale.